This invention is concerned with pulling over and toe lasting machines comprising a shoe support for supporting, bottom down, a shoe comprising an upper on a last and an insole on the last bottom, a plurality of pincers including at least one toe pincer and two sets of side pincers, the pincers being arranged in a generally U-shape about the shoe support for gripping lasting marginal portions of the shoe upper and tensioning the upper about its last, and a wiper assembly by which lasting marginal portions of the upper tensioned as aforesaid are wiped over and pressed against corresponding marginal portions of the insole, the assembly comprising two wiper plates disposed symmetrically at opposite sides of the longitudinal center line of the operating locality of the machine.
Machines of the aforementioned type are generally well known and conventional, see e.g. GB-A No. 2114868. Furthermore, in order to be able to accommodate the side pincers to different shoe widths, in machines of the aforementioned type each pincer is mounted for individual adjusting movement relative to the shoe support both lengthwise and widthwise of the bottom of a shoe supported thereby, thus to enable the operator to adjust the position of the pincers to the particular size and style of shoe being operated upon. In practice, however, it has been found that the operator tends to set the side pincers merely to the shape of the largest shoe in order to avoid the time-consuming individual adjustment of the side pincers in order to accommodate smaller shoes. Such a practice, however, does not enable the best lasting results to be obtained from the machine.
Also in pulling and lasting machines of the aforementioned type, it is desirable that the machine can readily operate on both left and right shoes without the need for the operator to adjust the pincers for that purpose. In setting up the machine, the operator will usually arrange the pincers symmetrically about a longitudinal centerline(s) of the operating locality of the machine, about which centerline(s) the wipers are also disposed symmetrically. This is justified in that the toe end of a shoe is generally considered to be symmetrical about a longitudinal centerline(s) of the toe end region, which line runs lengthwise of the shoe and intersects the toe end thereof. However, such symmetry extends only over a relatively small portion of the toe end of the shoe so that in what may be termed the forepart region, lying between the toe end and ball region, the shoe bottom is not symmetrical but rather, if the longitudinal centerline(s) of the operating locality and of the toe end region are in alignment, the "inside" forepart region of the shoe will be spaced further from the pincers than the "outside" forepart region. To accommodate this, furthermore, in practice the operator sets the pincers to such "outside" region. Such setting has the effect of unevenly pulling the upper on the last, thereby detracting from the achievement of optimum lasting results. It would not, however, be practicable using a conventional machine for the operator to set the side pincers for left and right shoes individually.
It has been proposed in GB-A No. 871990 to allow the pincers to move individually, i.e. independently of one another, from an outwardly spaced position inwardly to a position determined by engagement with the shoe bottom periphery of an abutment associated with each pincer, thereby setting the position of each pincer automatically according to the periphery of the shoe bottom. This arrangement however leads to an expensive machine construction which cannot be considered to be justified in terms of enhanced performance.
Furthermore, it is proposed in U.S. Pat. No. A 1441210 to provide, in a pulling over machine, a toe pincer and two side pincers arranged one at each side of the toe pincer, the side pincers each being mounted on a swinging arm the axis of rotation of which extends approximately vertically to the shoe bottom, one at each side of the toe pincer, and locking means being provided for securing each arm in adjusted position. In this way, the operator can readily re-position each pincer, thus to accommodate two shoes of different widths. With this arrangement however, the swinging of the arm provides the only adjustment of each pincer; that is to say the pincer is not adjustable relative to the arm. Consequently such an arrangement would not be suitable for incorporation into currently available pulling over and lasting machines, where more than one pincer would have to be mounted on each arm and be adjustable to accommodate different styles of shoe. Furthermore, even if such an arrangement were used, it could be expected that adjustment by the operator would be made only infrequently, as is the current practice (see above).